ICAR AICE-JRF/SRF Quality Assurance, Statistical Quality Control & Laboratory Management: practice questions

1 · Quality, quality control and quality assurance · easy

Which statement best distinguishes quality assurance from quality control in a dairy?

1. QA builds a preventive system that gives confidence; QC detects nonconforming product
2. QA tests finished product at dispatch, while QC audits the farms that supply the milk
3. QC is carried out only by certification bodies, while QA is carried out by plant staff
4. QA and QC are two names for the same laboratory testing done at milk reception

2 · Control charts for variables and attributes · medium

Fill weights of 500 g cups are charted in subgroups of 5. The average range is 12 g. With D3 = 0 and D4 = 2.114, what is the upper control limit of the R chart?

1. 6.9 g
2. 24.0 g
3. 36.0 g
4. 25.4 g

3 · Control charts for variables and attributes · medium

Subgroups of 5 butter samples give an average moisture range of 0.93%. With d2 = 2.326, what is the estimated process standard deviation?

1. 0.40%
2. 2.16%
3. 0.19%
4. 0.31%

4 · Process capability · medium

Why is a capability index calculated from data of an out-of-control process misleading?

1. Capability indices can only be calculated for attribute data such as leakers
2. An out-of-control process always gives a capability index of zero
3. An unstable process has no stable distribution to compare with the limits
4. The specification limits change whenever the process is out of control

5 · Six Sigma and lean in dairy plants · easy

What is the correct sequence of 5S?

1. Shine, sort, sustain, standardise, set in order
2. Sort, shine, set in order, sustain, standardise
3. Sort, set in order, shine, standardise, sustain
4. Set in order, sort, standardise, shine, sustain

6 · Six Sigma and lean in dairy plants · hard

Which lean improvement most directly reduces milk solids lost to effluent at product changeovers?

1. Increasing the speed of the filler above its rated speed
2. Adding an extra inspection of every case at dispatch
3. Pigging lines and sequencing products from plain to flavoured
4. Holding larger stocks of finished product in the cold store for longer

7 · ISO/IEC 17025 and laboratory accreditation · easy

In ISO/IEC 17025:2017, impartiality and confidentiality are addressed in which clause?

1. Clause 7, process requirements
2. Clause 6, resource requirements
3. Clause 4, general requirements
4. Clause 8, management system

8 · Laboratory audits and proficiency testing · hard

Routine mid-infrared milk analysers used for payment are kept accurate mainly by:

1. Annual replacement of the infrared source lamp only
2. Comparing results only with those of the previous day
3. Adjusting results until they match the farmers' expectations
4. Regular calibration against reference-method values on calibration milks

9 · Shelf-life determination · easy

A product's sensory score falls linearly (zero order) from 9.0 by 0.25 points per day, and the product is rejected below 6.0. What is its sensory shelf life?

1. 24 days
2. 12 days
3. 6 days
4. 36 days

10 · Shelf-life determination · medium

Why is accelerated shelf-life testing at 30–37 °C unreliable for chilled pasteurised milk?

1. Sensory panels cannot taste milk stored above room temperature
2. Pasteurised milk cannot be stored above 7 °C under any circumstances
3. The spoilage organisms at high temperature differ from those at chill
4. Q10 values for milk are always exactly 1.0